WIS stands for Warehouse Inventory System. It is an inventory system designed to be simple to use and adaptable to most common inventory systems.
It includes Item Master Edit for creating inventory items and locations, Purchase Orders for receiving items into inventory, Invoices for removing products from inventory, and physcial inventory for checking that the computer is tracking accurate values.

There are two versions of the inventory system, a simple one and a more complex one. The simple system tracks on hand quantities for items at a single location. Quantities are added to the on hand total manually, and quantities are removed from inventory via the scanner.

The advanced version of the inventory system uses Purchase Orders to add to inventory, as well as showing if an item is on order. When a Purchase Order is received, the on hand quantity is increased and the on order quantity is decreased.
It uses Invoices to reduce inventory. When an Invoice is created (like when a customer places an order with you), it increases the on reserve quantity for the item. When the Invoice (or order) is actually shipped, the on reserve quantity is decreased, and the on hand quantity is also decreased.
It also includes a physical inventory function that tracks beginning balance, receipts (incoming), disbursements (outgoing), and ending balance. It compares the ending balance to the current on hand value and generates an adjustment to make the on hand value match the ending balance.
Typically the physical inventory function is used to verify the system is working correctly and to adjust for inventory shrinkage due to damage or loss. It can also be used to calculate usage and/or receipts if one or the other is not tracked directly. For example, if only receipts are recorded in the system throughout the month, the disbursements (or usage) can be calculated by taking a physical inventory
and letting the system calculate the adjustment.

Scanners can be used in all sections of the advanced system. They can be used to add to inventory when a purchase order is received by scanning each item received and entering the quantity.
They can be used when an invoice (order) ships by scanning all items being shipped and entering the quantity shipped.
they can be used for physical inventory to scan items in the warehouse and enter the quantity present. Each of these types of scans can be uploaded to the system and the proper adjustments made to the inventory system.